Testing Beating Degree Or Freeness In Paper Making?

Beating degree is also called OSR in paper producing. Degree of beating is one of an index to reflect water filtration degree of difficulty. In general, the bigger of beating degree, the lower of filtration speed. Diluting 2g dry pulp to 1000ml, under certain temperature condition( such as 30°C ), through the 80 mesh, the amount of water discharged from the Shobel beater, is the result of the measurement.

There are many factors to influence the pulp dehydration, but the influence for these factors to paper nature is different. For example, fiber fibrosis can influence pulp’s dehydration, but can improve the paper strength; However, fiber’s cutting have influence to stock’s dehydration too, but can lower paper’s strength.

Thus visible, the determination of beating degree can’t distinguish them. And though the beating degree can comprehensively indicate that the fibers are cut, split, swell and hydrate, but it can not simply completely represent the nature of the slurry, still need other ways to detect together to judge the actual condition of beating slurry effect for fiber.